When I used Spotify I had wished my podcasts were able to be there since it would be convenient to just have the tracks in the same UI.
What I wanted though was just the ability to add podcasts via the open protocol url for them (how every other podcast app works) or for them to allow hosts to upload tracks.
Spotify instead saw an aggregation play - they could pay hosts for exclusivity and take those podcasts away from their open distribution into a distribution entirely controlled by Spotify. This is a hostile move to end users (and ultimately most content creators too in the end).